<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
</head>
<body>
    <div>07-sleep</div>
    <script>
       function sleep(delay){
        return new Promise(resolve=>{
            setTimeout(resolve,delay)
        })
       }
</script>
</body>
</html>
